Integrated Process For Making Inflatable Article

ABSTRACT

An integrated process for making an inflatable laminated article comprises extruding a first film and a second film, followed by cooling the first film and the second film so that the films will not fuse to one another upon contact with each other. The films are then brought into contact with one another, and selected portions of one or both films are heated so that the films are heat sealed to one another in a selected area having a desired pattern. The unsealed area between the film provides inflatable chambers between the first film and the second film. An alternative process utilizes a film tubing in lay-flat configuration to produce a laminated inflatable article.

FIELD OF THE INVENTION

The present invention relates generally to methods of making laminatedfilm articles, apparatus for making laminated film articles, and moreparticularly, to apparatus and methods for making laminated filmarticles having inflatable chambers and channels.

BACKGROUND OF THE INVENTION

Conventional cushion materials include thermoformed sealed laminatearticles such as Bubble Wrap® cushioning material. However, it is alsoknown to prepare laminated inflatable articles which can be shipped to apacker uninflated, and inflated immediately before use. Such inflatablearticles are typically made from two heat sealable films which are fusedtogether in discrete areas to form one or more inflatable chambers.

Conventional methods of making cushion material, such as Bubble Wrap®cushioning material, use a vacuum source to deform polymer film to formbubbles or pockets that can be filled with air (or other gases) to formbubbles. Such products can be made using a heated drum having recessesthat are connected to a vacuum source. When vacuum is applied, each ofvarious regions of the heated film in contact with the drum is drawninto a recesses on the drum. The heated film is deformed and thinned inthe regions drawn into the recess by the vacuum process. One side of theresulting film remains “flat”, while the other side is not flat, butrather is “thermoformed”. A second film, which preferably is a flatfilm, i.e., not thermoformed, is fused to the “flat side” of the formedfilm, resulting in a plurality of sealed, air-filled “bubbles.”

Conventional cushion fabricating processes also include a first stagefilm fabrication step and a separate second stage fusing step. In thefirst stage, polymer films are fabricated by conventional techniquesknown to those in the art of polymer film fabrication. In the secondstage, the polymer films are combined according to heat sealing methodsthat are known to those in the art of polymer film sealing techniques.

Two-stage manufacturing processes are undesirable because of the addedcost and inefficiency associated with the process. During two stageprocesses, films are fabricated and wound onto rolls at one location,and unwound and combined with a second film to make a cushioningmaterial at a second location. The processes are inefficient in thatthey include winding and unwinding of rolls of film, together withinventorying and transporting, as well as other inefficienciesassociated with two-stage processes.

SUMMARY OF THE INVENTION

The present invention overcomes the inefficiencies and other detrimentsdescribed above with an integrated, one-stage process for making aninflatable laminated inflatable article. The process of the inventionuses a single stage to go from polymer extrusion to form the film orfilms, thereafter sealing the film or films together to form inflatablechambers between the films.

As a first aspect, the present invention is directed to an integratedprocess for making an inflatable laminated article, comprising the stepsof: (A) extruding a first film and a second film; (B) cooling the firstfilm and the second film so that the films will not fuse to one anotherupon contact with each other; (C) contacting the first film with thesecond film; (D) heating selected portions of at least one of the firstand second films to a temperature above a fusion temperature, so thatthe first and second films are heat sealed to one another at a selectedarea, with the selected area providing a heat seal pattern in which theunsealed portions between the films provide inflatable chambers betweenthe first film and the second film. Of course, if one or more of thefilms are multilayer films having a sealing layer, the heating of suchfilm need only be to a temperature above the fusion temperature of atleast the seal layer of one or more of the films.

While it is preferred to have the C and D steps in this order, they maybe reversed in order, i.e., by first heating selected portions of atleast one of the films followed by contacting the first film with thesecond film so that the first and second films are heat sealed to oneanother at selected areas. Moreover, the selected areas need notcorrespond exactly with the selected portions which are heated. That is,the portions which are heat sealed may be slightly larger or slightlysmaller than the selected portions which are heated.

While the cooling can be active (e.g., contacting one or more films withone or more chilled rolls, belts, the use of cool air or water, etc.),it can also be passive, e.g., simply providing the first and secondfilms enough time to cool under ambient conditions so that they do notfuse to one another upon contact. Thereafter, in order to heat seal thefilms to one another, it is necessary to heat at least the seal layersof one or both of the films to a temperature at or above a temperatureat which the one or more of the seal layers will fuse.

Preferably, the first and second films are extruded simultaneously.Although it is possible to extrude both films from the same extruder(followed by separation from one another), preferably the first andsecond films are extruded using separate extruders. Either or both thefirst and second films can be extruded using an annular die or a slotdie, i.e., as an annular film or as a flat film, respectively. If anannular die is used, the resulting lay-flat tubing can either beself-welded into a flat film, or converted to a flat film by being slitin the machine direction.

Preferably, the contacting of the first film with the second film iscarried out by forwarding the first film and second film together at thesame speed. Although heating of selected portions of one or more of thefilms can be carried out before the films contact one another,preferably the heating of the selected portions of the first and secondfilms is carried out while the first and second films are in contactwith one another, with the heat sealing being carried out using acombination of heat and pressure. In one embodiment, the contacting stepand the heating step are performed simultaneously, with pressure beingsimultaneous with the heating, resulting in contacting and heat sealingbeing essentially simultaneous. During sealing, preferably heat andpressure are applied simultaneously.

Preferably, heating is performed by passing the first and second filmstogether through a nip between a first roll and a second roll, with atleast one of the rolls having a patterned raised surface and at leastone of the pair of rolls being heated. Preferably the patterned roll isheated. However, both the first roll as well as the second roll can beprovided with a raised surface, with the raised surfaces beingoperatively aligned to heat seal the selected portions of the first filmand the second film. Preferably, each roll with a raised surface has acontinuous raised surface so that the nip between the first and secondrolls is maintained throughout rotation of the first and second rolls,without further means to maintain the nip. If a roll does not have araised surface, preferably such roll has a smooth continuous surface toensure that the nip is maintained throughout rotation of the roll.Alternatively, means can be provided to maintain the nip betweenirregular rolls, such as a resilient surface on one or more of therolls, and/or a roll on a moveable axis with force continuously urgingthe rolls into contact with one another despite irregularities.Preferably, the first and second films are heat sealed to one another ina repeating pattern of sealed and unsealed areas.

As a second aspect, the present invention is directed to an integratedprocess for making an inflatable laminated article, comprising the stepsof: (A) extruding a tubular film having an outside surface and an insidesurface; (B) cooling the tubular film to a temperature low enough thatthe inside surface of the tubular film is cool enough not to adhere toitself; (C) placing the tubular film into the lay-flat configurationhaving a first lay-flat side and a second lay-flat side, so that a firstinside lay-flat surface of the first lay-flat side of the tubular filmis in contact with a second inside lay-flat surface of the secondlay-flat side of the tubular film; and, (D) heating sealing selectedportions of the first lay-flat side of the tubular film to the secondlay-flat side of the tubular film, the heat sealing being carried out toprovide a pattern of sealed and unsealed areas with the unsealed areasproviding inflatable chambers between the first lay-flat side of thetubular film and the second lay-flat side of the tubular film. Dependingupon the pattern of the heat sealing, the resulting heat sealed (i.e.,laminated) article may or may not have to be slit along one or both sideedges (i.e., slit in the machine direction) in order to provide accessfor means for inflating the inflatable chambers. The second aspect ofthe present invention is preferably otherwise carried out in accordancewith preferred features set forth above in the first aspect of thepresent invention.

As a third aspect, the present invention is directed to an integratedprocess for making an inflatable laminated article, comprising the stepsof: (A) extruding a flat film having a first outer surface and a secondouter surface; (B) cooling the film so that the first outer surface iscool enough not to adhere to itself upon being doubled back againstitself; (C) folding the film to make a crease in a machine direction ofthe film, with a first leaf of the film being on a first side of thecrease and a second leaf of the film being on a second side of thecrease, the first leaf being flat against the second leaf so that thefirst outer surface is doubled back against itself; and (D) heatingsealing selected portions of the first leaf to the second leaf, the heatsealing being carried out to provide a pattern of sealed and unsealedareas with the unsealed areas providing inflatable chambers between thefirst leaf and the second leaf. The third aspect of the presentinvention is also preferably carried out in accordance with preferredfeatures set forth above in the first aspect of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The numerous features and advantages of the present invention are betterunderstood by those skilled in the art by reference to the accompanyingdetailed description and the following drawing, in which:

FIG. 1 is a flow chart illustrating aspects of one stage integratedmethods of making laminate materials.

FIG. 2 is a diagrammatic view of one embodiment of an exemplary laminatemanufacturing system.

FIG. 3 is a diagrammatic view of another embodiment of an exemplarylaminate manufacturing system.

FIG. 4 is a diagrammatic view of another embodiment of an exemplarylaminate manufacturing system.

FIG. 5 is a diagrammatic view of another embodiment of an exemplarylaminate manufacturing system.

FIG. 6 is a diagrammatic view of another embodiment of an exemplarylaminate manufacturing system.

FIG. 7 is diagrammatic view of exemplary laminate manufacturingapparatus.

FIG. 8 is a diagrammatic view of a portion of the manufacturing process.

FIG. 9 is a diagrammatic view of another embodiment of a laminatemanufacturing apparatus.

FIG. 10 is a diagrammatic view of a particularly preferred laminatemanufacturing process.

FIG. 11 is an exemplary film manufacturing apparatus using a tubularstock of film to fabricate laminate material.

FIG. 12 is an exploded diagrammatic view of an exemplary laminatematerial.

FIG. 13 is a diagrammatic view of a section of an inflatable article.

DETAILED DESCRIPTION

Methods of making protective polymeric laminates, the laminatesthemselves, and apparatus for making the protective laminates aredisclosed. Protective laminates are made from two films, or from tubularstocks of film, in a one stage integrated in-line process. The laminatesare composed of discrete films sealed to each other in selected sealregions, forming a pattern of sealed and unsealed portions, the latterof which define chambers, inflation channels, connecting passageways, aninflation skirt, and optionally one or more inflation manifolds that canbe inflated, thereby ultimately (i.e., upon inflation and sealing toentrap the inflation gas or fluid) providing cushioning pockets orbubbles within the laminate. The present methods fabricate laminatematerials from polymeric resins in a one stage process that eliminatesdisadvantages associated with multiple stage processes.

FIG. 1 is a flow chart illustrating various steps of the one-stageintegrated method of making inflatable laminated articles in accordancewith the first aspect of the present invention. Reference numerals 1through 6 are employed to indicate the steps. The method of making theinflatable laminated article is carried out by extruding two films 1;cooling the films to a temperature below the fusing temperature of eachof the films 2; contacting the first and second films to each other 3,heating selected portions of the films 4, sealing the select heatedportions of the first film to the second film 5, and cooling the filmsto form the laminate material 6. Although cooling step 6 can be passive(e.g., in that the heat seals are simply allowed to cool by giving offheat to the ambient environment), it is preferably active in order toquickly cool the heat seals immediately after formation, so that theheat seal is not damaged or weakened by continued processing.

FIG. 2 is a diagrammatic view of one embodiment of an exemplary laminatemanufacturing system 10 a. Referring to FIG. 2 to illustrate methods ofthe present invention, the laminate manufacturing system 10 a comprisesextruders 11 and 11′, first and second films 12 and 13, transfer rollerpairs 14 and 14′, contact roller 15, and raised surface roller 16. Firstand second films 12 and 13 are extruded from separate extruders 11 and11′, respectively. After exiting extruders 11 and 11′, first and secondfilms 12 and 13 are cooled to a temperature just below the fusingtemperature of layers 12 and 13. Films 12 and 13 can be actively cooledby one or more of transfer rollers 14 or by exposure to ambientconditions. Transfer roller pairs 14 and 14′ guide first and secondfilms 12 and 13 to nip 17 formed between contact roller 15 and raisedsurface roller 16. As films 12 and 13 pass through nip 17, pressure isapplied to selected areas of both of films 12 and 13 whilesimultaneously heat is applied to at least one of films 12 and 13through at least one of rollers 15 and 16, so that heated portions offilms 12 and 13 are heat sealed to form heat seals in the sealed area,and inflatable chambers, passageways, etc in the unsealed area.

The present invention is inclusive of the heat sealing of two monolayerfilms to one another, heat sealing a multilayer film to a monolayerfilm, and heat sealing two multilayer films to one another.

FIG. 3 is a diagrammatic view of another embodiment of an exemplarylaminate manufacturing system 10 b. First and second films 12 and 13contact one another before first film 12 contacts raised surface roller16. Raised surface roller 16 heats selected portions of first film 12and simultaneously heats selected portions of second film 13 thatcorrespond to the heated portions of first film 12.

FIG. 4 is a diagrammatic view of an embodiment of alternative laminatemanufacturing process 10 c. In FIG. 4, first film 12 contacts raisedsurface roller 16 before first film 12 contacts second film 13. Selectedportions of first film 12 are heated by raised surface roller 16 beforefirst film 12 contacts second film 13, by advancing first film 12partially around raised surface roller 16 before passing films 12 and 13through nip 17.

FIG. 5 is a diagrammatic view of another alternative process 10 d formaking an inflatable article. In FIG. 5, first and second films 12 and13 are in mutual contact when first film 12 contacts raised surfaceroller 16 before the films enter nip 17. First film 12 and second film13 are heated by raised surface roller 16 as they are advanced throughnip 17 between raised surface roller 16 and associated smooth nip roller15.

FIG. 6 is a diagrammatic view of another alternative process 10 e formaking an inflatable article. In FIG. 6, the process further utilizescooling roller 18 to cool the heat sealed laminate 20 shortly aftersealing. First and second films 12 and 13 pass between nip 17 whereselected portions of films 12 and 13 are heat sealed. The heatedportions of films 12 and 13 are cooled, by cooling roller 18, to atemperature below the fusing temperature of films 12 and 13. In anotherembodiment (not illustrated), cooling roller 18 forms a nip with raisedsurface roller 16.

The one-stage process of the present invention eliminates the need towind-up component films 12 and 13 after extrusion but before lamination,as well as the need for transporting and unwinding such intermediateproducts. The integrated process involves controlling the temperature ofthe component films during fabrication, thereby providing films that arenot stressed during fabrication as in conventional two-stage processes.Preferably, the films are maintained at a temperature close to thefusing temperature of films, to minimize the stresses placed on thefilms. Minimizing temperature fluctuations yields laminate materialsthat are stronger and more durable than conventional packagingmaterials. The laminate materials made by the present methods are notinflated, which permits shipping an intermediate product or relativelyhigh density but which is ready for inflation at the location of theend-use, and this is more efficient than shipping a low density inflatedproduct.

The methods and apparatus of the present invention can be operated at ahigher output than conventional processes, including for example filmoutputs of more than 250 feet in length of film per minute. In addition,the methods produce larger width films than conventional processes,including for example, widths greater than 36 inches. The increase infilm width and in rate of film produced thereby permits an increase inthe surface area of laminated material produced more efficiently and atlower cost compared to conventional methods.

FIG. 7 is diagrammatic view of an alternative laminate manufacturingapparatus 19 a. FIG. 8 is an diagrammatic view of an alternativearrangement nip 17. The methods described herein are performed by anapparatus capable of adjusting the temperature of films to maximize filmfabrication speeds. Referring to FIG. 7 and FIG. 8, apparatus 19 a formaking laminate material 20 comprises extruder 11, transfer roller pairs14 and 14′, contact roller 15, raised surface roller 16, and collectionroller 21. Contact roller 15 and raised surface roller 16 areoperatively associated to form nip 17 which defines sealing zone 22.

FIG. 9 is a diagrammatic view of another embodiment of a laminatemanufacturing apparatus 19 b. Referring to FIG. 9, apparatus 19 bcomprises extruders 11 and 11′, transfer roller pairs 14 and 14′,contact roller 15, raised surface roller 16, cooling roller 18, andcollection roller 21.

Referring to FIG. 7, FIG. 8, and FIG. 9, transfer roller pairs 14 and14′ are conventional rollers familiar to persons skilled in the art ofpolymer film fabrication. With reference in particular to FIG. 7, thepresent invention is not limited to one transfer roller 14 or 14′, butrather encompasses one or more rollers that guide films 12 and 13 to nip17 as will be understood by persons familiar with film processingtechnology.

In one embodiment films 12 and 13 are cooled by transfer roller pairs 14and 14′, the cooling being to a temperature below the fusing temperatureof each of films 12 and 13. Transfer roller pairs 14 and 14′ are heattransfer rolls, cooled by conventional methods, such as cold watercirculated through the rolls. In embodiments of the present inventionhaving more than one transfer roller, it is preferred that transferroller pairs 14 and 14′ immediately prior to nip 17 cool films 12 and 13to a temperature below the fusing temperature of each of films 12 and13.

Referring to FIG. 7, FIG. 8, and FIG. 9, contact roller 15 opposesraised surface roller 16 and is operatively associated with raisedsurface roller 16 to form nip 17. Contact roller 15 applies pressure tofilms 12 and 13 as the films pass through nip 17. The present inventionis not limited to contact roller 15, but rather encompasses othercontact surfaces formed on other apparatus, such as a planer surfaces,curved surfaces, or portion of a clamp, as will be understood by personsfamiliar with film processing technology in view of the presentdisclosure.

With reference in particular to FIG. 8, contact roller 15 preferably hasan elastic outer layer 23. More preferably, the elastic outer layer 23is a smooth rubber layer. The elastic outer layer 23 is deformable andreadily conducts heat. The rubber outer layer 23 provides heat transferto the second layer 13 and diminishes the tendency of adherence of thesecond layer of film 13 to contact roller 15.

With reference in particular to FIG. 8, raised surface roller 16comprises raised surfaces 24, recesses 25, and recessed surfaces 26.Raised surface roller 16 is a heat transfer roller and is heated byconventional heating apparatus, as will be understood by personsfamiliar with plastic film and roller heating technology. Preferablyraised surface roller 16 is heated by hot oil.

The present invention is not limited to heat sealing using raisedsurface roller 16, but rather encompasses alternative forms of heatsealing apparati, including impulse sealing apparati, ultrasonicsealing, etc. The sealing means need not continuously seal the filmstogether, but rather can carry out the sealing intermittently. Moreover,the raised surface roller could alternatively be a planer surface,curved surface, or portion of a clamp, as will be understood by personsfamiliar with film processing technology in view of the presentdisclosure. The raised surface roller or plate does not require a sourceof vacuum.

The methods of the present invention have an advantage over conventionalmethods of making protective laminates and bubble film because thepresent methods do not require thermoforming of the structure of thelaminate material during the heat sealing process by vacuum stretchingthe films. However, the present invention is not limited to methods thatdo not distort, deform the films, but rather encompasses conventionalvacuum stretching techniques as will be understood by persons familiarwith film processing technology in view of the present disclosure.

Raised surfaces 24 and recessed surfaces 26 form a patterned heat seal27 in laminate material 20 as explained more fully below with referenceto FIG. 13. Raised surfaces 24 extend away from recessed surfaces 26thereby forming a pattern for the heat seal(s) to be made to form theinflatable article. The pattern formed by raised surface 24 is such thatraised surfaces 24 are in contact with contact roller 15 when raisedsurface roller 16 is in contact with contact roller 15. Recess surfaces26 are not in contact with contact surface 16 when raised surface roller16 contacts contact roller 15.

With reference in particular to FIG. 8, in one embodiment of the presentinvention, raised surface roller 16 further comprises a release coating28 that reduces adherence with film 12 while film 12 contacts raisedsurface roller 16, and particularly when film 12 releases from roller16. A portion of release coating 28 is infused with one or morepolymers. The polymer infused can be any conventional polymer used forreducing adherence to polymer films, for example, Teflon®polytetratluoroethylene. Raised surface roller 16 can be infused by anyconventional infusion process. Preferably, the raised surface of roller16 is textured to reduce adherence to polymer films, as discussed inmore detail below.

In an alternative embodiment of the present invention (not illustrated),contact roller 15 has raised surfaces that correspond to raised surfaces24. Contact roller 15 has recesses and recessed surfaces that correspondwith recesses 25 and recessed surfaces 26.

Referring to FIG. 7 and FIG. 8, raised surface roller 16 and contactroller 15 are operatively associate to form a nip 17. The term “nip” asused herein refers to an area between two rollers. First film 12 andsecond film 13 are in contact as they pass though nip 17. As first andsecond films 12 and 13 pass through nip 17, heat and/or pressure areapplied to the films such that selected portions of first and secondfilms 12 and 13, fusing the films together to form patterned heat seals27.

In FIG. 9, extruders 11 and 11′ are conventional extruder. First andsecond films 12 and 13 can be extruded as monolayer films, coextruded asmultilayered films, extruded through an annular die or slot die, orextrusion coated which are familiar to persons familiar with plasticfilm manufacturing technology. In one embodiment first and second films12 and 13 are toughened by crosslinking via chemical cross-linking orirradiation techniques known to those of skill in the art.

In the embodiment as shown in FIGS. 2-7, and 9 extruder 11 can be one ormore extruders.

In another embodiment as shown in FIG. 11, a film tubing, in lay-flatconfiguration, is of course integrally joined at its edges. However, thetwo lay-flat sides are used to form laminated inflatable article 20. Insuch a process, only one extruder is needed, the extruder feeding amolten stream of polymer to an annular die from which the film tubing isextruded. Optionally, a second extruder can be used to extrusion coatthe tubular film with one or more film layers by extrusion coatingtechniques known to those skilled in the film fabrication arts.

FIG. 10 is a schematic of a particularly preferred apparatus and process(50) for carrying out the present invention. In FIG. 10, extruders 52and 54 extrude first film 56 and second film 58, respectively. Afterextrusion, film 54 makes a partial wrap around heat transfer (cooling)roller 60, which preferably has a diameter of 8 inches and which ismaintained at a surface temperature well beneath the fusion temperatureof the extrudate, e.g., from 100-150° F. Second film 56 makes partialwraps around each of heat transfer (cooling) rollers 62 and 64, each ofwhich has a diameter of 8 inches and each of which is maintained at asurface temperature similar to that of cooling roller 60. After cooling,first film 56 makes a partial wrap (about 90 degrees) around Tefloncoated rubber nip roll 66, which has a diameter of 8 inches and whichhas, as its primary function, maintaining nip with heat transfer(heating) raised surface roll 70. While first film 56 is passing overnip roll 66, second film 58 merges with first film 56, with both filmstogether being wrapped for a short distance around nip roll 66 beforetogether entering first nip 68. Nip roller 66 provides a location offilms 56 and 58 to come together without being marred or distorted.

Thereafter, second film 58 makes direct contact with raised surface roll70 (which is illustrated as a smooth roll only for simplicity ofillustration). First nip 68 subjects films 56 and 58 to a pressure offrom 2 to 10 pounds per linear inch, preferably 2 to 6 pounds per linearinch, more preferably about 4 pounds per linear inch.

Films 56 and 58 together contact raised surface roll 70 for a distanceof about 180 degrees. Raised surface roll 70 has a diameter of 12inches, is heated by circulating hot oil therethrough so that thesurface is maintained at a temperature of from 280° F. to 350° F., andhas edges of the raised surfaces being rounded over to a radius of 1/64inch. Raised surface roll 70 has a Teflon® polytetratluoroethylenecoating thereon, with the raised surfaces being above the background bya distance of ¼ inch (0.64 cm). Moreover, the raised surface of raisedsurface roll 70 is provided with a surface roughness of from 50 to 500root mean square (i.e., “rms”), preferably 100 to 300 rms, morepreferably about 250 rms. This degree of roughness improves the releasequalities of raised surface roll 70, enabling faster process speeds anda high quality product which is undamaged by licking back on roll 70.

The raised surface heats that portion of film 58 which contacts theraised surface of roll 70. Heat is transferred from raised surface roll70, through a heated portion of film 58, to heat a corresponding portionof film 56 to be heat sealed to film 58. Upon passing about 180 degreesaround raised surface roll 70, heated films 58 and 56 together passthrough second nip 72, which subjects heated films 58 and 56 to aboutthe same pressure as is exerted in first nip 68, resulting in apatterned heat seal between films 56 and 58.

After passing through second nip 72, films 58 and 56, now sealedtogether, pass about 90 degrees around heat transfer (cooling) roller74, which has a diameter of 12 inches and which has cooling waterpassing therethrough, the cooling water having a temperature of from100° F. to 150° F. Cooling roller 74 has a ¼ inch thick (about 0.64 cmthick) release and heat-transfer coating thereon. The coating is madefrom a composition designated “SA-B4”, which is provided and applied toa metal roller by Silicone Products and Technologies Inc of Lancaster,N.Y. The coating contains silicone rubber to provide cooling roller 74with a Shore A hardness of from 40 to 100, preferably 50-80, morepreferably 50-70, and still more preferably about 60. The SA-B4composition also contains one or more fillers to increase the heatconductivity to improve the ability of cooling roller 74 to cool thestill hot films, now sealed together to result in inflatable article 76,which is thereafter rolled up to form a roll for shipment and subsequentinflation and sealing, to result in a cushioning article.

In order to carry out the process at relatively high speed, e.g., speedsof at least 120 feet per minute, preferably from 150 to 300 feet perminute, but up to as high as 500 feet per minute, it has been found tobe important to provide the manufacturing apparatus with severalfeatures. First, the raised surface roll should be provided with arelease coating or layer, and to also avoid sharp edges which interferewith a clean release of the film from the raised surface roll. As usedherein, the phrase “release coating” is inclusive of all releasecoatings and layers, including polyinfused coatings, applied coatingssuch as brushed and sprayed coatings which cure on the roll, and even arelease tape adhered to the roll. A preferred release coatingcomposition is Teflon® polytetrafluoroethylene. Second, the edges of theraised surfaces should be rounded off to a radius large enough that thefilm readily releases without snagging on an edge due to its “sharpness”relative to the softened film. Preferably, the radius of curvature isfrom 1/256 inch to ⅜ inch, more preferably from 1/128 inch to 1/16 inch,more preferably from 1/100 inch to 1/32 inch, and more preferably about1/64 inch, i.e., about 0.04 cm. It is also important to provide thecooling roller downstream of and in nip relationship with the raisedsurface roller, with a release coating or layer, as described above.

The process and apparatus illustrated in FIG. 10 can also besupplemented with additional optional components and steps. Moreparticularly, one or both of films 58 and 62 can be preheated to atemperature below their fusing temperature, so that less heat need beadded by raised surface roller 70. In this manner, the process can beoperated at higher speed, and/or the heat seal may be made stronger orof otherwise higher quality. Preheating can be carried out by, forexample, providing nip roller 66 with heating characteristics inaddition to providing raised surface roller 70 with heatingcharacteristics. Optionally, additional nips can be provided againstraised surface roller 70, to provide additional pressure points for theformation of strong heat seals at high manufacturing speeds.

FIG. 11 is a diagrammatic view of an exemplary film manufacturingapparatus using a tubular stock of film to fabricate laminate material.Referring to FIG. 11, extruder 11 comprises resin hopper 30, body 31,and die 32. Extruder 11 can be any conventional extruder, including forexample, single screw, double screw, and/or tandem extruders. In anotherembodiment, one or more extruders connected to die 32 co-extrude, asmultilayer film or monolayer film, polymers having different propertiesor compositions.

Referring to FIG. 11 to illustrate methods of extruding films, films arefabricated by providing resin pellets 33 to resin hopper 30 of extruder34, from which resin pellets 33 are fed into extruder 34. Resin pellets33 are melted in extruder 34 to form a molten resin stream. Optionaladditives can be added to the molten resin stream in a separate streaminjected into extruder 34 and/or added to the extruder on or with theaddition of resin pellets 33 to hopper 30. Extruder 34 forces the moltenresin stream through annular die 32 to form tubular film extrudate 12which is oriented in the machine and transverse directions while thepolymer is in the molten state (and while it cools). Orientation isgenerated by forcing the extrudate to enlarge to pass around a blownbubble of gas (providing orientation in the transverse direction), aswell as orientation generated by operating nip rolls 14 at a higherspeed than the speed of the molten extrudate emerging from the annulardie (providing orientation in the machine direction). The tubularextrudate 12 is collapsed into lay-flat tubing 29 after it cools to atemperature at which it will not self-weld. This process is known as a“blown” film process.

Lay-flat tubing 29 can then be converted into the inflatable article 20in the manner illustrated in FIG. 11 and as more particularlyillustrated in FIG. 8. Alternatively, lay-flat tubing 29 could also beconverted into the inflatable article using the arrangement illustratedin FIG. 10, with the lay-flat tubing 29 being the sole film being passedthrough the first and second nips 68 and 72, respectively, instead ofusing two separate films as illustrated in FIG. 10.

FIGS. 6, 8, illustrate embodiments of a system that further comprises acooling roller 18. FIG. 10 illustrates corresponding cooling roller 74.These cooling rollers are to be maintained at a temperature below thefusing temperatures of films, using conventional cooling techniques. Thecooling roller solidifies the heated portions of the first and secondfilms. The present invention is not limited to one cooling roller 18,but rather further encompasses the use of two or more cooling rollers inthe process, i.e., downstream of the heated raised surface roller.Moreover, any suitable means for cooling could be used in place of oneor more cooling rollers, such as cooled planer surfaces, cooled curvedsurfaces, cooled clamping surfaces of any shape, cool fluids and gases,etc., as will be understood by persons of skill in the art of filmmanufacture and processing.

The cooling roller lowers the temperature of the selected heatedportions of the laminate, in order to cool the heat seals so that theybecome strong enough to undergo further processing without being damagedor weakened. Moreover, the cooling means is preferably immediatelydownstream of the heating means (i.e., the raised surface roll), inorder to reduce heat seepage from the still-hot seals to unheatedportions of film, to prevent unheated portions of laminated article frombecoming hot enough to fuse the films in an area intended to serve as aninflation chamber or inflation passageway.

FIG. 12 is an exploded diagrammatic view of an exemplary laminatematerial 20. FIG. 13 is a diagrammatic view of a section of a preferredlaminated inflatable article produced in accordance with the presentinvention. Referring to FIG. 12 and FIG. 13, laminate material 20comprises first film 12 heat sealed to second film 13 in a particularheat seal pattern. Laminate 20 has heat sealed portion 40, as well asunsealed portion 41. Heat sealed portion 40 is continuous along themachine direction of inflatable laminate article 20, with sealed portion40 corresponding to a preferred raised surface pattern for raisedsurface roller 16 (FIG. 11) or 70 (FIG. 10). Unsealed portion 41 is alsocontinuous along the machine direction of article 20, with unsealedportion 41 corresponding to a preferred recessed surface pattern (i.e.,background pattern) of raised surface roller 16 and 70. Unsealed portion41 is arranged to form a pattern that includes distinct air chambers,connecting channels, as well as leaving a skirt (i.e., film flaps) foruse in inflating the inflatable article. Optionally, the unsealedportion could further include a passageway in the machine directionwhich serves as a manifold, i.e. connecting each of the passagewaysalong an edge of the article. However, a skirt is preferred.

The films referred to herein preferably comprise a polyolefin, such asfor example a low density polyethylene, a homogeneousethylene/alpha-olefin copolymer (preferably a metallocene-catalyzedethylene/alpha-olefin copolymer), a medium density polyethylene, a highdensity polyethylene, a polyethylene terapthalate, polypropylene, nylon,polyvinylidene chloride (especially methyl acrylate and vinyl chloridecopolymers of vinylidene chloride), polyvinyl alcohol, polyamide, orcombinations thereof.

Preferably, laminate materials 20 are as thin as possible, in order tominimize the amount of resin necessary to fabricate laminate materials20, but at the same time are thick enough to provide adequatedurability. Preferably, first and second layers film 12 and 13 have agauge thickness of from about 0.1 to about 20 mils. More preferably,each film layer has a total gauge thickness from about 0.5 to about 10mils, more preferably from about 0.8 to about 4 mils, and even morepreferably from about 1.0 to about 3 mils.

If desired or necessary, various additives are also included with thefilms. For example, additives comprise pigments, colorants, fillers,antioxidants, flame retardants, anti-bacterial agents, anti-staticagents, stabilizers, fragrances, odor masking agents, anti-blockingagents, slip agents, and the like. Thus, the present inventionencompasses employing suitable film constituents.

Preferably first and second films 12 and 13 are hot blown films havingan A/B/C/B/A structure which has a total thickness of 1.5 mils. The Alayers together make up 86 percent of the total thickness, each of the Blayers making up 2% of the total thickness, and the C layer making up10% of the total thickness. The C layer is an O₂-barrier layer of 100%Caplon® B100WP polyamide 6 having a viscosity of Fav=100, obtained fromAllied Chemical. Each of the B layers are tie layers made of 100%Plexar® PX165 anhydride modified ethylene copolymer from QunatumChemical. Each of the A layers are a blend of 45% by weight HCX002linear low density polyethylene having a density of 0.941 g/cc and amelt index of 4, obtained from Mobil, 45% by weight LF10218 low densitypolyethylene having a density of 0.918 g/cc and a melt index of 2,obtained from Nova, and 10% by weight SLX9103 metallocene-catalyzedethylene/alpha-olefin copolymer, obtained from Exxon.

The laminates formed according to the present invention will resistpopping when pressure is applied to a localized area because channels ofair between chambers provide a cushioning effect. The laminates alsoshow excellent creep resistance and cushioning properties due tointer-passage of air between bubbles.

The various terms and phrases utilized throughout this document are tobe given their ordinary meaning as understood by those of skill in theart, except and to the extent that any term or phrase used herein isreferred to and/or elaborated upon in U.S. Pat. No. 5,837,335, toBabrowicz, entitled High Shrink Multilayer Film which Maintains Opticsupon Shrinking, issued Nov. 17, 1998, which is hereby incorporated inits entirety by reference thereto, and which supplements the ordinarymeaning of all terms, phrases, and other descriptions set forth herein.

In the figures and specification, there have been disclosed preferredembodiments of the invention. All sub-ranges of all ranges disclosed areincluded in the invention and are hereby expressly disclosed. Whilespecific terms are employed, they are used in a generic and descriptivesense only, and not for the purpose of limiting the scope of theinvention being set forth in the following claims.

Those skilled in the art will appreciate that numerous changes andmodifications may be made to the embodiments described herein, and thatsuch changes and modifications may be made without departing from thespirit of the invention.

1-18. (canceled)
 19. An integrated process for making an inflatablelaminated article, comprising the steps of: (A) extruding a tubular filmhaving an outside surface and an inside surface; (B) cooling the tubularfilm to a temperature low enough that the inside surface of the tubularfilm is cool enough not to adhere to itself; (C) placing the tubularfilm into a lay-flat configuration having a first lay-flat side and asecond lay-flat side, so that a first inside lay-flat surface of thefirst lay-flat side of the tubular film is in contact with a secondinside lay-flat surface of the second lay-flat side of the tubular film;and (D) heat sealing selected portions of the first lay-flat side of thetubular film to the second lay-flat side of the tubular film, bybringing the first lay-flat side of the tubular film into contact with aheated raised surface roller, with the first lay-flat side of thetubular film contacting and passing in partial wrap around the heatedraised surface roller, with the heated raised surface roller heatingselected portions of the first and second lay-flat sides of the tubularfilm to a temperature above the fusion temperature while the first andsecond lay-flat sides of the tubular film remain in contact with oneanother, with the heat sealing being carried out to provide a pattern ofsealed and unsealed areas with the unsealed areas providing inflatablechambers between the first lay-flat side of the tubular film and thesecond lay-flat side of the tubular film; and (E) winding up ortransporting the inflatable laminated article with the inflatablechambers uninflated.
 20. An integrated process for making an inflatablelaminated article, comprising the steps of: (A) extruding a flat filmhaving a first outer surface and a second outer surface; (B) cooling theflat film so that the first outer surface is cool enough not to adhereto itself upon being doubled back against itself; (C) folding the flatfilm to make a crease in a machine direction of the flat film, with afirst flat leaf of the flat film being on a first side of the crease anda second flat leaf of the flat film being on a second side of thecrease, the first flat leaf being flat against the second flat leaf sothat the first outer surface is doubled back against itself; (D) heatsealing selected portions of the first flat leaf to the second flatleaf, the heat sealing being carried out by bringing the first flat leafof the flat film into contact with a heated raised surface roller toheat selected portions of the first and second flat leaves to atemperature above the fusion temperature, with the first flat leaf ofthe flat film contacting and passing together in partial wrap around theheated raised surface roller while the first and second flat leaves ofthe flat film remain in contact with one another, to provide a patternof sealed and unsealed areas with the unsealed areas providinginflatable chambers between the first flat leaf and the second flatleaf; and (E) winding up or transporting the inflatable laminatedarticle with the inflatable chambers uninflated.
 21. The processaccording to claim 19, wherein the selected portions of the first andsecond lay-flat sides of the tubular film are heat sealed to one anotherusing a combination of heat and pressure.
 22. The process according toclaim 19, wherein the cooling step comprises contacting the tubular filmwith at least one cooling roller.
 23. The process according to claim 19,wherein the heated raised surface roller has a continuous raised surfacetherearound.
 24. The process according to claim 19, wherein the firstand second lay-flat sides of the tubular film are heat sealed to oneanother to provide a repeating pattern consisting of sealed areas andunsealed areas.
 25. The process according to claim 19, wherein theheated raised surface roller has a release coating thereon.
 26. Theprocess according to claim 25, wherein the release coating has a surfaceroughness of from 50 to 500 RMS.
 27. The process according to claim 26,wherein the release coating comprises a polyinfused coating.
 28. Theprocess according to claim 27, wherein the polyinfused coating comprisespolyinfused polytetrafluoroethylene.
 29. The process according to claim28, wherein the release coating on the heated raised surface roller hasa surface roughness of from 50 to 500 rms.
 30. The process according toclaim 19, further comprising cooling the first and second lay-flat sidesof the tubular film after heating the selected portions of the first andsecond lay-flat sides of the tubular film, the cooling being carried outby passing the first and second lay-flat sides of the tubular filmtogether in a partial wrap around a cooling roller.
 31. The processaccording to claim 30, wherein the cooling roller has a release coatingthereon.
 32. The process according to claim 31, wherein the releasecoating on the cooling roller has a Shore A hardness of from 40 to 100.33. The process according to claim 19, wherein the first and secondlay-flat sides of the tubular film are forwarded at a speed of at least120 feet per minute, and the heated raised surface roller has a releasecoating thereon and raised surface edges rounded off to a radius of from1/256 inch to ⅜ inch, and further comprising a cooling roller downstreamof and in nip relationship with the heated roller, the cooling rolleralso having a release coating thereon.
 34. The process according toclaim 33, wherein the first and second lay-flat sides of the tubularfilm are forwarded at a speed of from 120 to 500 feet per minute, andthe release coating on the cooling roller having a Shore A hardness offrom 40 to
 100. 35. The process according to claim 19, wherein aftercooling, the first and second lay-flat sides of the tubular film make apartial wrap around a roller which is upstream of the heated raisedsurface roller.
 36. The process according to claim 35, wherein theroller which is upstream of the heated raised surface roller is in niprelation with the heated roller having the raised surface.
 37. Theprocess according to claim 19, further comprising passing a contactroller in nip relationship with the heated raised surface roller, withthe first and second lay-flat sides of the tubular film passing throughthe nip between the contact roller and the heated raised surface roller,with the contact roller applying pressure to the first and secondlay-flat sides of the tubular film as the first and second lay-flatsides of the tubular film pass through the nip between the contactroller and the heated raised surface roller.
 38. The process accordingto claim 37, wherein the contact roller has an elastic outer layer.